When something is working, active, or happening. It's the opposite of 'off'.
The TV is on.
The party is on for tonight.
I left the stove on by accident!
To continue doing something, or to keep going.
The show must go on!
He talked on and on about his vacation.
Let's move on to the next topic.
To wear something or have something attached to you.
She had a beautiful dress on.
He put his shoes on.
I have a lot on my plate right now.
